The present invention addresses a common problem encountered by users of imaging apparatus. More specifically, the present invention provides for methods and apparatus to reduce the likelihood that special imaging media is printed with the wrong print job.
Imaging apparatus, as the term is used herein, include printers (such as self-standing units and table-top computer printers, for example), photocopiers, and other apparatus which are configured to generate an image on imaging media. Non-limiting examples of imaging media include paper, transparencies, card stock, envelopes, and labels. The present invention is particularly useful for imaging apparatus which generate an image on imaging media using a digital file (a “print file”) as the image source. The invention is also particularly useful for imaging apparatus which are used in a shared manner within a computer network. That is, a computer network can include a central server which is configured to direct print jobs from a number of different user stations to a central imaging apparatus. (A “print job” is a digital file containing instructions to allow the imaging apparatus to generate an image, such as text and/or graphics, on imaging media.) The user stations can be, for example, computer workstations or desk-top computers. The network configuration thus allows a plurality of users to access one or more imaging apparatus, reducing the number of imaging apparatus required to support all of the users.
Imaging apparatus are generally configured with one of more primary media trays. (Imaging media trays are commonly known as “paper trays”, although the use of the term should not be considered as limiting the type of media contained in the tray.) For example, an imaging apparatus can have a first paper tray configured to hold letter-sized paper, and a second paper tray configured to hold legal sized paper. In addition to the primary media tray(s), an imaging apparatus can include a priority imaging media tray, also known sometimes as a bypass tray. The priority tray allows a user to print a print job on specialty imaging media (i.e., imaging media not contained in the primary tray(s)) without having to remove the imaging media in the primary tray(s). For example, a user may desire to print an address on an envelope, or print a sheet of adhesive labels. Accordingly, the user will load the desired specialty media into the priority media tray, and then print the desired image onto the specialty media.
Many prior art imaging apparatus which contain a priority media tray are configured to require an additional drive mechanism to allow the user to associate a print job with the media within the priority tray. This is accomplished by providing the imaging apparatus with a priority tray media detection device (such as a switch or a sensor) which detects the presence of media within the priority tray. When media is detected in the priority tray, the imaging apparatus actuates media feed components (mostly comprising feed rollers) to pull media from the priority tray, and to print the next-received print job onto that media. Other prior art imaging apparatus have only a single feed mechanism comprising a feed roller which picks or feeds media from a common feed area. In this configuration, both the primary media tray and the priority media tray position media in the common feed area, and the feed roller thus feeds the next sheet of media presented to the roller. A problem with this configuration is that the user can insert specialty media into the priority tray, but then may send a different print job (i.e., a print job not intended to be imaged onto the specialty media) to the imaging apparatus, forgetting that the imaging apparatus has been loaded with specialty media. The result is that the print job is imaged onto the specialty media, when it was not intended to be. That is, since the imaging apparatus has no way to differentiate one type of media from another, the next print job received by the imaging apparatus will be imaged onto the media in the priority tray, whether it was intended to be or not. This results in wastage (primarily of the specialty media), as well as lost time since the user will need to reprint the print job once it has been discovered that the print job was imaged onto the wrong media.
What is needed then are methods and apparatus to allow the use of a priority media tray with an imaging apparatus which achieves the benefits to be derived from similar prior art methods and apparatus, but which avoids the shortcomings and detriments individually associated therewith.